1. Field of the Invention
The present invention relates to an apparatus and a method for local anesthesia, more precisely an apparatus and a method for local anesthesia particularly indicating exactly an anesthesia region and enabling the injection to be administered around the anesthesia region through a plurality of anesthesia needles.
2. Description of the Related Art
Anesthesia indicates unconsciousness, painless, or elimination of body reaction that might interrupt operation. Anesthesia has always been with the history of mankind. In particular, anesthesiology (anesthesia science) has made remarkable progress since ether was used for general anesthesia in the 16th century.
In general, if anesthesia includes all of the unconsciousness, painless, and elimination of body reaction that might interrupt operation above, it is called general anesthesia. If anesthesia only works for a local area without losing consciousness, it is called local anesthesia or regional anesthesia.
Regional anesthesia includes spinal anesthesia, epidural anesthesia, and local anesthesia, etc. Epidural anesthesia is divided according to the region where an anesthetic drug is administered by an injection needle into thoracic epidural anesthesia, lumbar epidural anesthesia, and caudal epidural anesthesia. Regional anesthesia includes infiltration anesthesia, field block anesthesia, and peripheral nerve block anesthesia, etc.
Spinal anesthesia, epidural anesthesia, and caudal anesthesia are old anesthetic methods which have been used even before the development of anesthesia devices because they can be performed without complicated equipments, and are still frequently performed.
Recently, the development of new local anesthetics, the use of opioids, and the importance of acute and chronic pain management have become more common. According to the recent development of new local anesthetics and the use of opioids, along with the increasing interest on acute and chronic pain control, the anesthetic methods above are being more common. Spinal anesthesia is also called subarachnoid anesthesia because it is the method of administering local anesthetics to the cerebro-spinal fluid (CSF) in the subarachnoid space. Epidural anesthesia is a method of administering local anesthetics to the epidural space between the dura meter and the ligamentum flavum. In particular, the administration of local anesthetics into the epidural space of the sacrum is called caudal epidural anesthesia. When spinal anesthesia is performed, the injected local anesthetic spreads through the cerebrospinal fluid and the blocking zone is determined according to the spread range. At this time, only a small amount of local anesthetic is required. In the meantime, epidural anesthesia is only working in the limited region injected with local anesthetics, and requires a large amount of local anesthetics, compared with spinal anesthesia. Epidural anesthesia is working slowly but is able to maintain the anesthetic status for a long time by injecting local anesthetics through a catheter.
The methods for anesthesia above are called regional anesthesia because they only anesthetize a part of the body, or they are called conduction block because they block the neural pathway without losing consciousness of the patient. These methods for local anesthesia can avoid side effects or complications accompanied by general anesthesia and do not cause pain in patients after surgery.
However, for the regional anesthesia, multiple injections of anesthetics are required which causes pain. To solve the problem, the present inventors have proposed an apparatus and a method for local anesthesia which can accurately indicate the affected part of an anesthetic object and can reduce pain during anesthesia.